Waste Silk Research Articles

Highly porous carbon with rich inherent groups for ultrahigh adsorption of organic dyes from wastewater

Activated carbon from renewable biomass or its waste to purify various dyeing wastewater from textile industry is highly desired. In this work, porous activated carbon was prepared by using silk waste as precursor via a simple one-step carbonization process. The obtained SWC-1-800 had ultrahigh adsorption for anionic dye AR73 and cationic dye MB owing to its ultrahigh specific surface area (2774 m2 g−1) and rich functional groups. SWC-1-800 had an increased adsorption capacity reaching 1310 and 928 mg g−1 for AR73 and MB respectively as the initial concentration up to 1000 mg L−1. Moreover, the adsorption capacity was stable under a wide range of Na+ and SDS concentration. By adjusting the temperature and pH value, the maximum adsorption capacity reached 1337 and 1000 mg g−1 for AR73 and MB respectively, keeping the removal rate of AR73 and MB more than 80 % after 5 adsorption cycles. Besides, SWC-1-800 demonstrated quite good adsorption ability for many other kinds of dyes, which adsorption capacity as high as 1998 mg g−1 (Rh B). The adsorption mechanism was further proposed according to the structural characteristics, inherent functional groups and adsorption properties. Using silk waste-derived carbon to effectively absorb the harmful dyes in the wastewater shows dual value for cleaner production via a “waste-waste to clean products” model, which has great application potential in dyeing wastewater purification.

Karnataka and India’s Silk Industry: A Comprehensive Analysis of Sericulture Dynamics

India is the second largest producer of silk with 36,453 MT (2022-23) after China and also the largest consumer of silk in the world. Asia is the main producer of silk in the world and produces over 95 per cent of the total global output. In India, mulberry silk is produced mainly in the states of Karnataka, Andhra Pradesh, Tamil Nadu, Jammu & Kashmir and West Bengal, while the non-mulberry silks are produced in Jharkhand, Chattisgarh, Orissa and North-Eastern states. Much of silk exports earnings is from silk garments, silk carpets and silk wastes, which is about 1,773.38 crore Rs. in total in 2022–23. Mulberry is the largest contributor to the total raw silk production with the compound annual growth rate of 3.09 per cent at 1 per cent level of significance. Tasar silk production registered highest growth rate of 13.67 per cent at 1 per cent level of significance and Jharkhand is the major contributor of about 80 per cent for the total tasar silk production. Karnataka is the leading producer of mulberry silk whereas Assam is currently the largest producer of Vanya silk. Telangana registered a highest compound annual growth rate of 21.1 per cent at 1 per cent level of significance followed by Maharashtra (16.9%). Ramanagara is having highest area under mulberry (20804.56 hectares) followed by Chikkaballapura (20544.62 hectares) and Kolar (19907.79 hectares) in Karnataka.

Study on the performance of Co–Ni sulfide electrocatalysts supported by different fibroin-based carbon precursors

Research on sustainable energy sources is crucial for alleviating environmental issues and addressing energy security concerns. This study investigates the utilization of various silk precursors in the hydrogen evolution reaction. Waste silk fabric, regenerated silk fibroin film, porous silk fibroin, silk cocoon and degummed silk fibroin were used as precursors to prepare HER electrocatalysts. To investigate the influence of precursor form on catalytic perform9ance, a comparative analysis of the morphology, structure and composition of different materials was conducted. Among various catalysts, waste silk fabric based catalysts exhibit the most excellent catalytic activity, with an overpotential of 113 mV at 10 mA cm−2 and a Tafel slope of 30.9 mV/dec. Even After 1000 cycles of testing, it still maintains excellent catalytic activity. This study provides insights into the influence of precursor forms on the electrochemical performance of biomass carbon-based catalysts, aiming to inspire further research in this field.

Effects of different cocoon-stifling methods on the reeling and quality characteristics of raw silk

In this study, we evaluated the effects of five stifling methods on the reeling parameters and raw silk characteristics of double hybrid cocoons. The methods were open sun drying, sun drying under a black cloth, drying in the SKUAST-K-fabricated solar cocoon dryer, multifuel hot air drying, and hot air drying. Our findings showed that hot air drying produced the best results in terms of reeling parameters, i.e. average filament length (805.750 m), average non-breakable filament length (800.750 m), average denier (2.777), renditta (2.805), silk waste percentage (15.17), raw silk percentage (30.382), reelability percentage (80.982), and degumming loss percentage (16.285). The method also yielded superior results for raw silk characteristics, such as winding (0.000 breaks), evenness first (1.000 count), evenness second (0.000 count), neatness percentage (95.000), cleanness percentage (96.500), tenacity (4.032 g/denier), elongation percentage (23.000), and cohesion (68.250 strokes). The SKUAST-K-fabricated solar cocoon dryer produced the second-best results.

Primary processing technology of silk waste for use in silk industries

Primary processing technology of silk waste for use in silk industries

Waste silk selvedge/glass fiber reinforced strip-shaped composite: A critical assessment of twisting and dyeing of silk on mechanical properties

With about 11 million tons of waste silk produced each year, waste silk reinforced composites are an important way of high-value utilization. However, the mechanical stability of waste silk reinforced composites remains to be further studied. In this study, we evaluate the flexural and impact properties of waste silk selvedge/glass fiber reinforced strip-shaped composites with different twisting and dyeing structures. The findings reveal that both twisting and dyeing of silk negatively affect the mechanical properties. The twisting structure introduces yarn discontinuity, leading to a 33 % reduction in impact strength. The dyeing process disrupts silk's β-sheet structure, causing a more disordered β-strand structure and a decrease in flexural strength from 448.4 MPa to 412.4 MPa. Further, we determined that untwisting and undyeing waste silk selvedges are suitable for impact-critical application such as automotive bumper. While the twisting and dyeing waste silk selvedges are suitable for non-structural applications requiring aesthetic appeal, such as automotive interiors.This study identifies critical factors influencing mechanical properties of waste silk reinforced composites, benefiting their engineering applications.

Biomass-based porous carbon from trachycarpus fortunei silk with the hierarchical oxygen-enriched structure for high performance flexible all-solid-state supercapacitor

Hierarchical porous carbons with diverse pore scales are commonly chosen as electrode materials for high-performance supercapacitors due to their excellent electrochemical properties. Herein, a novel synthetic method, dilute H2SO4 pretreatment coupling with subsequent KOH activation, is adopted to prepare hierarchical oxygen-enriched porous carbon using trachycarpus fortunei silk (TFSPC) waste as the raw material. The optimized TFSPC2 possesses a 2049 m2 g−1 specific surface area, 1.58 cm3 g−1 total pore volume, and 22.54 at% oxygen-containing doping. Benefiting from such characteristics, the TFSPC2 electrode exhibits an excellent specific capacitance of 469 F g−1 at 0.5 A g−1 and remarkable cycling stability of only 4.94% capacitance decay even after 20000 uninterrupted cycles in a 6 M KOH electrolyte. Furthermore, the assembled flexible symmetric supercapacitor device TFSPC2//TFSPC2 achieves a high energy density of 14.60 Wh kg−1 in a potential range of 0–1.3 V when the power density is 320 W kg−1. More importantly, the TFSPC2//TFSPC2 device demonstrates superior mechanical flexibility and maintains 88.70% capacity retention even through 2000 cycles (90°) of reduplicative bending/recovering. The research provides a low-cost, green, and renewable strategy for the synthesis of hierarchical porous carbons for supercapacitors.

Silk wastes and autoclaved degumming as an alternative for a sustainable silk process

Silk degumming is considered the first point in the preparation of silk-based materials since this process could modify the silk fiber and the properties of its related products. This study evaluated the differences in morphology, secondary structure, amino acid content, thermal stability, and mechanical properties of two types of raw materials, defective cocoons (DC) and silk fibrous waste (SW), degummed by chemical (C) and autoclaving (A) methods. Subsequently, silk fibroin films were prepared by dissolving each type of degummed fibers, and thermal and structural films properties were determined. The findings demonstrated that autoclaving is an efficient alternative to remove silk sericin, as the resulting fibers presented improved structural, thermal, and mechanical properties compared to those obtained by the chemical method. For films preparation, autoclave resulted in a good option, but dissolution parameters need to be adjusted for defective cocoons. Furthermore, similarities between the physicochemical properties of fibers and films from both fibrous wastes suggest that SW is a promising raw material for producing fibrous resources and regenerated silk fibroin materials. Overall, these findings suggest new recycling methods for fibrous waste and by-products generated in the silk textile production process.

Silk Nonwoven: Recycling and Upcycling of Waste Silk into Bio-based Materials with High Value-Added Properties

Silk Nonwoven: Recycling and Upcycling of Waste Silk into Bio-based Materials with High Value-Added Properties

Comparison study on dye degradation by PDA-SF/AgNPs-H2O2 and PDA-SF/AgNPs-PMS catalytic system

In this work, polydopamine (PDA) was used to facilitate the reduction of silver nitrate (AgNO3) to silver nanoparticles (AgNPs) and the simultaneous loading on waste silk fabrics (PDA-SF/AgNPs). The removal activity of the obtained composite PDA-SF/AgNPs on different dyes in the presence of hydrogen peroxide (H2O2) and potassium peroxymonosulfate (PMS) was compared. The effects of reaction temperature, H2O2/PMS dosage, dye concentration, composite dosage, electrolyte concentration and time in two catalyst systems on the dye removal were discussed. The results showed the dye removal of Telon Red A2R reached 81% and 95% in 30–50 min in PDA-SF/AgNPs-H2O2 and PDA-SF/AgNPs-PMS system, respectively. Quenching experiments demonstrated that ·OH, ·O2– and SO4-· were produced during the degradation process, and the possible degradation pathway of Telon Red A2R were analyzed by HPLC-MS. In addition, the kinetic study indicated that the removal of dye followed quasi-second-order adsorption kinetics. These findings suggest that fabric-based composites have great potential and applications in catalysis and treatment of wastewater.

The Current State and Prospects of Recycling Silk Industry Waste into Nonwoven Materials

Natural fibres are the preferred options for garment, technical and medical textiles, nonwovens and composites. Their sustainability is a considerable advantage, though the nature of silk production and processing involves a large amount of waste. The present review explores the current issues of recycling silk waste into nonwovens for various purposes. The article proposes obtaining nonwovens from short fibres using electrospinning of fibroin solutions in volatile solvents. Longer fibres are proposed to be processed into needle-punched nonwoven materials with a selection of an effective antistatic treatment.

Sustainable Antibacterial Surgical Suture Based on Recycled Silk Resource by an Internal Combination of Inorganic Nanomaterials.

The current antibacterial treatment methods of silk sutures can only be finished by surface modification, leading to problems of short antibacterial effects, easy slow-release consumption, prominent toxicity, and susceptibility to drug resistance. Speculatively, surgical sutures combining antibacterial material internally will possess a more promising efficacy. Hence, we extracted recycled regenerated silk fibroin (RRSF) from waste silk resources to make RRSF solutions. Internally combining with inorganic titanium dioxide (TiO2) nanoparticles, we fabricated antibacterial RRSF-based surgical sutures. The morphologies, mechanical and antibacterial properties, biocompatibility tests, and in vivo experiments were carried out. The results showed that the surgical sutures with 1.25 wt % TiO2 acquired 2.40 N knot strength (143 μm diameter) and achieved a sustainable antibacterial effect of 93.58%. Surprisingly, the sutures significantly reduced inflammatory reactions and promoted wound healing. Surgical sutures in this paper realize high-value recovery of waste silk fibers and provide a novel approach to preparing multifunctional sutures.

Surface functionalized waste-silk fabric engineered with polylactic acid & activated charcoal for oil/solvent recovery from oily wastewater

The present study reports using waste silk fabric functionalized using Polylactic acid (PLA) and Activated charcoal for oil/solvent recovery from simulated seawater (3.5% NaCl-based water). An average of 91% separation was visible in the functionalized waste silk fabric with an efficiency up to 20 cycles towards petroleum oils/solvents from simulated seawater. Further, the functionalized waste fabric showed hydrophobic properties with a water-based contact angle of 105° and oil/solvent absorption towards petroleum oils and organic solvent, with a surface free energy of 52.46 mN m−1. The functionalized waste silk also showed permeation flux of 658, 386, and 993 L m−2 h−1, for Petrol, Diesel, and n-Hexane, respectively. The results show that PLA/Activated-charcoal engineered waste silk can be effectively applied for practical oil/solvent recovery from simulated seawater. Utilizing waste silk fabric further supports in reducing the global carbon footprints as silk does not emit and/-or produce carbon dioxide due to its green origin and generating the circular economy approach.

Effect of Degumming Duration on the Behavior of Waste Filature Silk-Reinforced Wheat Gluten Composite for Sustainable Applications.

Silkworm silk proteins are of great importance in several fields of science owing to their outstanding properties. India generates waste silk fibers, also known as waste filature silk, in abundance. Utilizing waste filature silk as reinforcement in biopolymers enhances its physiochemical properties. However, the hydrophilic sericin layer on the surface of the fibers makes it very difficult to have proper fiber-matrix adhesion. Thus, degumming the fiber surface allows better control of the fiber properties. The present study uses filature silk (Bombyx mori) as fiber reinforcement to prepare wheat gluten-based natural composites for low-strength green applications. The fibers were degummed in sodium hydroxide (NaOH) solution from a 0 to 12 h duration, and composites were prepared from them. The analysis exhibited optimized fiber treatment duration and its effect on the composite properties. The traces of the sericin layer were found before 6 h of fiber treatment, which interrupted homogeneous fiber-matrix adhesion in the composite. The X-ray diffraction study showed enhanced crystallinity of the degummed fibers. The FTIR study of the prepared composites with degummed fibers showed that shifted peaks toward lower wavenumbers supported better bonding among the constituents. Similarly, the tensile and impact strength of the composite made of 6 h of degummed fibers showed better mechanical properties than others. The same can be validated with the SEM analysis and TGA as well. This study also showed that prolonged exposure to alkali solution reduces the fiber properties, thus reducing composite properties too. As a green alternative, the prepared composite sheets can potentially be applied in manufacturing seedling trays and one-time nursery pots.

Pemanfaatan Rambut Jagung (Zea mays L.) Menjadi Teh Herbal “KoNsilk” kepada Kader Puskesmas Perumnas 2 Kota Pontianak

The impact of the Covid-19 pandemic is felt by the people of Pontianak, in the economic, sociocultural, and health fields. One of the prime commodities in Pontianak is corn farming. The aim of the PKM Program is to innovate corn-based processed products. This PKM activity began with outreach to the heads and employees of the Puskesmas, as well as identifying health cadres as potential participants in training related to using corn silk as herbal tea drinks. Training on using corn silk as herbal tea drinks for cadres was carried out offline and interactively using leaflets, videos, and hands-on practice. Evaluation and monitoring activities are carried out using a Google form (pre-test and post-test). The results of the PKM activity showed success in understanding the cadres with good knowledge when the pre-test was carried out by only ten people (30.30%). After being given knowledge training, respondents in the good category amounted to 30 people (90.90%). PKM activities targeting UPT Puskesmas Perum II cadres increased the ability of cadres to utilize corn silk waste in herbal tea. The next activity is expected to be able to assist so that the resulting product obtains a permit.

The Effect of Ratio of Methanol and Concentration of Methanol in Corn Silk Extracts with Ultrasonic-assisted Extraction

Cornsilk refers to stigmas of female maize flowers. Corn silk contains abundant flavonoids. Flavonoids show a variety of biological activities, such as antioxidants. Several methods, such as microwave, ultrasonic, supercritical fluid extraction, and multiple extraction technologies, were used to extract flavonoids from corn silk. The ultrasonic-assisted extraction method (UAE) seems to be very reliable among these methods. UAE has the advantage of simplicity and can be easily implemented with other extraction techniques. Hence, the current study aimed to determine the effect of the ratio (material: methanol) and concentration of methanol corn silk extracts in UAE. The experimental design used was a factorial Randomized Completely Block Design (RCBD) with two factors and three replications for each treatment. The two treatments were: A1=methanol (1:4) (w/v), A2=methanol (1:6) (w/v), A3=methanol (1:8) (w/v) and methanol concentration (60, 70 and 80%). Results showed that the ratio of methanol and concentration had a significant effect (p<0.05) on nutritional and phytochemical content in corn silk extracts. The best treatment interaction on A3B3 (1:8 (w/v) and methanol concentration 80% with nutritional content analysis (water 6.38%, ash 1.11%, fat 0.44%, protein 4.70%, carbohydrates 87.23%, and dietary fiber 2.72% and the analysis of phytochemicals content (total phenol 2.91 µg GAE/g, flavonoids 2.32 µg GAE/g, beta carotene 1.07 ppm, vitamins C 12.47 mg, and antioxidant activity 27.08%). The implication of this study is that corn silk extracts could be developed as a source of nutrients and bioactive compounds, and corn silk waste can be converted into value-added products.

Mechanical and acoustic properties of alkali treated agricultural waste reinforced sustainable polyurethane composites

In this research, polyurethane (PU) foam composites were prepared by using various agricultural waste (rice husk, corn silk, artichoke stem) particles. In order to enhance the compatibility and adhesion between the waste particle and PU matrix, alkali treatment was employed. The alkali treated particles were chemically and morphologically characterized by Fourier transform infrared (FTIR) spectroscopy, cellulose determination instrument, and scanning electron microscopy (SEM), respectively. The effects of the alkali treatment on the structural, morphological, mechanical, and acoustic properties of the overall PU foam composites were all examined. Due to the differences in chemical compositions of the agricultural wastes, the alkali treatment affected the acoustic and mechanical properties of the PU foam composites in varying ratios. The PU foam composite reinforced with alkali treated artichoke stem waste particles showed the highest tensile strength value of 265 kPa, whereas the highest sound absorption value of 40.5% as an enhancement on the acoustic properties compared to the blank PU foam composite was recorded in corn silk waste particle loaded sample.

Waste silk fabric derived N-doped carbon as a self-supported electrocatalyst for hydrogen evolution reaction

Developing a highly efficient, stable and cost-effective electrocatalyst is critical for Hydrogen Evolution Reaction (HER). Herein, we present a facile approach for constructing self-supported N-doped carbon electrocatalysts derived from waste silk fabric for HER. After activation of KCl and the thermal carbonization process, the resulting catalysts present a unique porous three-dimensional(3D) structure that can expose more active sites and will promote the efficient diffusion of the electrolyte. As an N-rich and self-supported HER catalyst, the synthetic materials exhibit outstanding electrocatalytic performance with the overpotential of 336.33 ± 26.22 mV to achieve a current density of 10 mA cm−2 and long-term stability (more than 24 h). This work will explore a completely novel approach to prepare a variety of self-supporting 3D electrodes from biomass for various applications.

Production and mechanical characterization of reinforced zinc oxide nanoparticle-coated silk waste bio-composites

Production and mechanical characterization of reinforced zinc oxide nanoparticle-coated silk waste bio-composites

Needle punched nonwoven silk waste material with antifungal properties for air filtration

ABSTRACT The paper presents an effective antistatic composition for forming the web from silk waste on a carding machine. As a result, the needle punched nonwoven material modified with silver and copper nanoparticles was obtained from Bombyx mori natural silk. The specific surface area of the material is 0.223 m2/g, the average size of macropores is 85 μm; the minimum is 30 μm and the maximum is 370 μm. The holding capacity in case of dolomite dust is 99.4%. The presence of silver and copper nanoparticles gives the material antifungal properties that remain stable after no less than 4 washings.